The present invention relates to the vehicle sector, in particular for hybrid and electric vehicles. The present invention particularly relates to the disconnection of a high-voltage in a vehicle during servicing and/or in the event of a fault.
Electrical components of a hybrid or electric vehicle are usually operated at voltages which are dangerous to people. To prevent a voltage of this kind from endangering the health or the life of a person, it is necessary to ensure that said voltage is not transmitted to live components of the vehicle or exposed to open access during servicing or in the event of a fault, and as a result does not present a potential hazard.
To this end, conventional hybrid and electric vehicles have substantially encapsulated components by which direct access to voltage-carrying parts from outside is prevented. However, in the event of a fault or during servicing, it may be necessary to release high-voltage cabling arrangements between the components or to open the housings thereof. In the event of an accident, intervention of this kind may be forced from the outside.
In a case of this kind in which the integrity of the high-voltage circuit or its insulating insulation means is no longer ensured, care must be taken that high-voltage-carrying components are not exposed in such a way that unprotected access from the outside is possible.
As a result, contact elements, which detect disconnection of the high-voltage cabling or of the housing and trigger high-voltage disconnection of the entire system in response, are used locally on the housings or plug elements of the electrical circuit of the high-voltage-carrying components.
A corresponding measure can be seen in a so-called high-voltage interlock, in other words disconnection of the hazardous voltage in high-voltage-carrying components if protective covers are removed or high-voltage-carrying plug connections are disconnected.
A functionality of this kind can conventionally be realized by what is known as a pilot line or high-voltage interlock line which is interrupted as soon as a plug or cover of high-voltage-carrying components is opened or released and therefore would expose a dangerous voltage.
In this case, the pilot line can be in the form of a serial contact interconnection and connected to a central evaluation element or an evaluation circuit. The serial interconnection of the contact elements to all high-voltage-carrying components of a vehicle has to ensure, in particular, that single component-independent opening or disconnection of a high-voltage-carrying element is sufficient to deactivate the entire system.
An associated evaluation circuit can be arranged, for example, in a pulse-controlled inverter or in the battery and can furthermore transmit a disconnection instruction to the remaining components of the system via a system bus or communication bus, for example a CAN bus.
By way of example, all sources which feed the intermediate circuit can be disconnected, the electrical drive can be disconnected and all relevant energy storage means can be discharged as system responses when the pilot line is open. Sources can be disconnected, for example, by opening the battery contactor, electrical drives can be disconnected by opening a clutch and stopping the drive or by active short-circuiting.
However, central disconnection of this kind is very complicated and costly since additional outlay on cabling, and plugs and contacts and a central evaluation circuit are required. In particular, an individual pilot line has to be serially routed through all of the high-voltage-carrying components in order to ensure reliable disconnection in the event of a fault and/or during servicing. However, a corresponding individual, serial pilot line can also be considered to be susceptible to faults.